### Simple Calculation for Speakers in Parallel

If all the speakers in parallel have the same impedance, then the calculation is easy. Simply divide the impedance by the number of speakers in parallel.

Example 1: Four 8 ohm speakers in parallel: 8 divided by 4 = 2 ohms.

Example 2: Two 4 ohms speakers in parallel: 4 divided by 2 = 2 ohms.

### Not so Simple Calculations for Speakers in Parallel

For calculations involving speakers in parallel with different impedance, the following formula is required (it can be used with speakers of similar impedances too).

If you have a calculator with *1/x* button then this calculation is not too difficult. If you don’t have that function on your calculator, or if you don’t like formulas, check out the calculators below.

### Calculator for Speakers in Parallel

Below is my new calculator for 2, 3 or 4 speakers wired in parallel.

Simply type the impedance of each speaker into the white boxes (or use the drop-down values). Use N/A for unused speakers in this calculator. The total impedance will be calculated for the entered speakers.

Also for each speaker is a calculated percentage. The shows how the power output of the amplifier is shared between the speakers. Power sharing is a consideration when using speakers with different impedance. See How Multiple Speakers Share Power for further details.

The final calculation is labelled “Power Differential”. This calculates in dB (decibels) the power level difference between the highest and lowest power as it is shared across the speakers in parallel. This shows the power level difference when using speakers with different impedance.

This calculator will help you understand the total speaker load on your HiFi amplifier. For a better understanding of this and what to do about it, read the articles How do I Connect Multiple Speakers to my HiFi Amplifier and How to wire four HiFi speakers or How to connect 2 speakers to one amplifier or watch the video in the article Understanding Speaker Impedance.

Note: all these calculations are for connecting manufactured speakers (boxes). They are not used when building your own speaker boxes and connecting multiple speakers in a cabinet using a crossover circuit. A crossover splits the signal into different frequencies for each of the speakers and makes the total impedance calculation complex (as impedance is frequency dependent). That is why speaker designers get the big money, and as installers we benefit from their expertise.

If you need further advice on connecting speakers in parallel, please read the FAQs before submitting your question. You also find an answer in the comments below.

Hi Geoff!

I have amplifier which have Dynamic Power 160 W (3 ohms, Front) 125 W (4 Ohms, Front) 85 W (8 Ohms, Front),

I have 6 speakers with 16W 8ohms, can I run them?

Thanks

Hi Salman,

The figures are saying the absolute mimimum total load impedance for the amp is 3 ohms. But probably best to keep above 4 ohms for each channel. Connecting 6 speakers wired in parallel will give a total load impedance of speakers to one amp of only 1.3 ohms. Therefore the easiest, way to connect 6 speakers to one amp would be to use a 6 (or 8) way speaker selector switch.

Geoff

Thanks Geoff,

I haven’t use any speakers selector before, I have searched some from amazon, I have seen only buttons as per number of speakers on front panel and two inputs and outputs for speakers, my question is will speakers selector configure it self as per need?

Thanks and regards

Hi Salman, A speaker selector switch will take care of the impedance issues, as a standard switch (with push buttons) should have a series resistor which wont let the amp see an impedance below 4 or 5 ohms. You can see this using the second of the speaker switch simulators. Alternatively, since it is a permanent install, you could run all 3 speakers in series for both the left and right channels. This will also limit the total impedance to safe levels. Really, the amp is designed as a surround sound amp for a lounge room, not to drive 6… Read more »

Hi Geoff,

I installed new speakers in my car which came with stock Bose speakers because of a deal Pontiac and Bose made back in the late 1990’s. I have 2 4Ohm 30RMS 2-way speakers and 2 4Ohm 75RMS 2-way speakers. I used the stock wires and the speakers are very quiet compared to the stock speakers. I couldn’t find anything on the specs of the Bose speakers or the amp. Would I need new wires or is the amp not putting enough power?

Hi Nick,

Most probably the Bose speakers were designed to make the amp look good. They may have been more sensitive (effiecient) hence they sounded louder.

I would not have thought changing cables is going to make any significant difference. It could be the amp needs to be more powerful, but it seems there is something else wrong if there is a huge difference between them. Have you tried connecting the Bose speakers back up to see if they are still the same loudness as before (even try with one).

Geoff

i have two 4 ohm dvc and a 1 channel amp. i need a 2 ohm load out

Hi Ced,

If you have two 4 ohms speakers conencted in parallel, then yes, you need an amp that can cope with a 2 ohm load. If you conenct them in series, then the total load impedance will be 8 ohms which most amps will be fine with.

Geoff

Hi Geoff,

I have an amp with 2 channel @ 4 ohm/750W each. (2x Left and 2x Right). I already installed 2 speakers @ 4 ohms/550W. Question is, can I add 2 more speakers so i can utelized the 2x Left and 2x Right. And what kind of speaker should I add so that the speaking or voice volume will increase. Effects and other sound are too loud while I cant barely hear the speaking voice.

Thanks in adnvace.

Hi Carlo, If your amp is designed for a minimum load impedance of 4 ohms, then you can’t add any more speakers. Adding another set of 4 ohm speakers will make the total load impedance 2 ohms for each channel, which is too low for most amps. It seems your problem isn’t power, as it is loud enough for music and sound effects. It could be that one of the existing speakers is out of phase. When speakers are out of phase it will sound fine with stereo sounds (like music and effects) as they are different on each channel.… Read more »

This will probably make me sound a fair bit dense, but what do the 1s represent in the formula. Following the formula gives me the correct answer, but why do we divide one by the number of ohms?

Hi Steven,

Good question. The 1 is used simply because you need to add the inverse of each impedance. That is, 1/impedance.

Is this what you were asking?

Geoff

Hi Geoff!

I have a amplifier and the lowest impedance rate of my amp is 2 ohms per channel

And I have 12 speakers of 8 ohm each and I need to connect 6 speakers on each channel

So my question is:

How can I wire up 6 speaker of 8 ohm each to get a total of 2 ohms load

Thanks!!

Hi Isaak, It is not possible to arrange six 8 ohms speakers to give you a total load impedance of 2 ohms. However 2 ohms is lowest the amp will work with, but it will also work with any impedance above 2 ohms, albeit with a sightly lower maximum output power. For example, if you connect 3 speakers in parallel, that gives you an impedance of 2.67 ohms. If you connect the other 3 speakers in parallel also, and then join both sets together in series, the total load impedance on the amp would be 5.3 ohms. The amp should… Read more »

Hi Geoff ,

I have an amplifier Yamaha rx-v365 ( Built-in 5-channel power amplifier ,(1 kHz, 0.9% THD, 6 Ω) ,Front: 100 ,W/ch , Center: 100 W , Surround: 100 W/ch ) and i want to connect 3 speakers eatch side of the front ( 1 – 80w – 8 Ohms , 2 – 100w 8 ohms , 3 – 100w 8 Ohms ) , How should i connect ? Parallel or Series , to not burst with any of the speakers or amplifier ? Thank you for your patience .

Hi Hugo, It is not simple to connect 3 sets of 8 ohm speakers. If you connect them in parallel, the total load impedance will be 2.6 ohms which is too low for the amp. If you connect them in series, the amp will be happier, but it will not produce as much power as it can. If you connect two in series and then in parallel with the third, then the sound level will not be even across the speakers. So using a speaker selector switch may be a better solution, Whatever method, the power from the amplifier will… Read more »

Designing Speaker System (Advice Needed) If I have a 700 Watt Stereo Power Amplifier (350 Watts Per Channel). I wish to wire a total of 8 speakers (4 Woofers each at 8 Ohms going to an inductor crossover & 4 Midrange Speakers each at 8 Ohms going through a 400 Volt Capacitor crossover) all together within one single speaker cabinet. How should I wire/configure this without overloading my power amplifier? 1. Woofer: Out of the four woofers (each 8 ohms) – can I safely wire each “pair” of woofers in series going to the amplifier; which will give me 4… Read more »

Hi AJ, Unfortunately I’m a not a speaker designer, so I may not be a lot of help. I can though comment on your calculations. You talk about wiring each pair in series, then you use the parallel calculation. That is to say, two 8 ohms speakers in series will give a total impedance of 16 ohms, not 4 ohms. Then two lots of 16 ohms in parallel will give you 8 ohms in total. However there is then the cross over to consider, as you say. This is where I’m out of my area of knowledge. I would think… Read more »

Hi Geoff, I am looking for amp specifications to drive 6 8ohm speakers in a single outdoor room. The speakers are 150w RMS. Been through way too many articles and getting confused. Wiring 3 in parallel gets me to 2.67 ohm, but that seems pretty low. Wiring in series gets me to 24 ohm…is that just too high? Advice welcomed.

Hi Pete,

As you have found, it is not easy to wire three speakers in series/parallel and get even power through each one.

I think the best way forward would be to wire all three in parallel, which would give you a load impedance of 2.7 ohms for each channel (as you say). Then use an amp which will work into 2 ohms. Something like the Crown XLS1000 will deliver 550 watts into 2 ohms with both channels working. They are reasonably priced too.

Does this help?

Geoff

I have an Episode 500 LCR speaker manufacturered by Snap AV

Link below ….

https://www.snapav.com/shop/en/snapav/episode-reg%3B-500-series-thin-design-3-channel-passive-soundbar-(each)

It is a 6 ohm speaker.

How can I rewire it so that all 3 channels operate as one ?

I’ve tried wiring it in series , doing it this way it sounds beautifully but it presents a 2 ohm load to the amplifier.

I’d like to rewire it so it works as a single 6 ohm speaker .

Currently my amplifier goes into safe mode and shuts down at high volume.

Hi Kevin, Thanks for the link, saves me some time and effort. It seems you actually wired all three in parallel to get your 2 ohm total impedance, and hence the amp not liking that and turning off to protect itself. It is not easy to wire 3 sets of 6 ohm speakers in any configuration to give a reasonable total impedance and a level power sharing between them. My best attempt is to forget the center channel, and wire the left and right in series. This will give a total load impedance of 12 ohms, which the amp should… Read more »